Ever since iPhoneOS (now iOS) has been released, there's an old fight going on about how multitasking should work on personal computers, and more specially what should happen to applications which are put in the background. Some advocate that they should be dipped in virtual liquid nitrogen and stop doing anything, like on iOS, which others advocate that they should continue to run in the background, like on desktop OSs. What about putting a little more flexibility in there?

Not quite. It's a bit more interesting. As has been mentioned multiple times, iOS 4 offers a number of hacks that allow to get around the "one task at a time" limitation for very specific purposes.

I know. That's why I said usually.

The thing is, it's not a sustainable model, because as more people figure out what they can develop, Apple will have to add more and more hacks or to ban more and more applications. But who could explain that to them ?

Explain what to whom? Certainly Apple's engineers are smart enough to know this. I have no doubt that, unlike the original MacOS, iOS is capable of doing real multitasking; unfortunately, it's not allowed to do so.